Inertia injector



Dec. 26, 1961 R..L. BROWN ET AI.

INERTIA EJECTOR Filed Jan. 13, 1958 INVENTORS' RICHARD L. BROWN EDWIN S VARTANIAN EDWARD L MORROW United States Patent 3,014,304 INERTIA INJECTOR Richard L. Brown, North Branford, Edward L. Morrow, Bridgeport, and Edwin S. Vartanian, North Haven, Conn., assignors to Olin Mathieson Chemical Corporation Filed Jan. 13, B58, Ser. No. 708,732 3 Claims. (Cl. 42-25) The present invention relates to firearms and in particularto a novel ejector device, hereinafter referred to as an inertia ejector.

The language inertia ejector is intended to define a member which, although movably mounted and freely movable, is effective to initiate ejection of a spent cartridge case while the member is at rest by virtue of its natural tendency to resist motion and remain at rest.

A particular feature of the present invention is its general simplicity and ease of fabrication.

Another feature of the present invention is the provision of a novel ejection device which is not rigidly secured to any element of a firearm.

A still further feature of the invention is the provision of a firearm having 'a floating ejector which is operable to develop a couple in cooperation with a fulcrum element to eject a spent cartridge.

A firearm embracing certain principlesof the present invention may comprise an extractor, a bolt, a receiver formed with an ejection port, a movable member disposed within the receiver operable to engage the rim of a spent cartridge and effective in cooperation with the extractor to develop a couple for ejecting the cartridge through said port, said member being movable independently of the bolt and the receiver and being effective to develop said couple primarily by virtue of its inertia.

Other features and advantages of the invention will become more apparent from a study of the succeeding specification when read in conjunction with the appended V drawings, in which:

FIG. 1 is a sectional view, in elevation, of a firearm with which the principles of the present invention may be utilized;

FIG. 2 is a transverse sectional view of the firearm of FIG. 1 as viewed in the plane of line 22.

Referring now to the drawings, there is shown a receiver 10 having a loading port 11, an ejection port 12, a bolt 13, and a firing pin 14.

The bolt is actuated by blowback action in well known fashion.

Since the principles of the present invention are readily adaptable to firearms having various operating characteristics or actions, only those portions of the exem plary firearm will be described in detail which are deemed necessary to illustrate the principles of the present invention.

An extractor, sometimes referred to as a fulcrum'elemeat, 16 is pivotally mounted to the bolt at 17 and the forward end thereof is formed with a claw 18 normally adapted to engage a portion of the rim 19of a cartridge 21 while the bolt is in the closed position as shown in FIG. 1.

Since the exemplary embodiment of the present invention is shown and'described as adapted to a firearm having a blow-back action, it is to be understood that the extractor shown is not needed to withdraw a spent case from chamber 22 upon firing. In well known fashion the spent case is blown to the rear automatically. On the other hand, the extractor is useful in the manual operation of the bolt and in the present invention serves as a pivot point or fulcrum element about which a spentcase is rotated during the course of automatic ejection.

Referring nowto FIG. 2, it is apparent that the bolt is Patented Dec. 26, 1961 2 V formed with a cut-out or groove 23 to provide clearance for an inertia ejector device indicated generally by the reference numeral 24.

The ejector 24 comprises an inertia member or rod 26 having a lip 27 at one end thereof and a bore 28 at the opposite end for receiving a guide pin 29.

The guide pin 29, suitably anchored in the receiver as at 31, is formed with a head 32 and carries an exceedingly light coil spring 33 operable in cooperation with the head 32 and a face 33A of the rod 26 to maintain the rod in a position shown in FIG. 1 hereinafter referred to as the ejection position.

In a manner which will become more apparent hereinafter the rod 26 is movable from the ejection position to the dotted line position thereof shown in FIG. 1 to clear the loading port '11.

It is to be clearly understood that although the rod 26 is nested within the bolt, there is no physical connection between the bolt and the rod.

Furthermore, the coil spring 33 exerts a very light pressure upon the inertia rod. In fact, the pressure need be no greater than is necessary to urge the member 26 to the right to the position shown in FIG. 1. The spring performs a negligible buffering action.

It is noted that the compressive resistance exerted by the coil spring 33 does not interfere with the removal of cartridges from the firearm chamber during manual op-' eration of the bolt. During manual operation, the cartridge rim of a cartridge being removed merely eases the inertia rod to the rear as the bolt is hauled to the rear. The couple effect, if any, developed during manual operation is negligible.

The device operates in the following fashion:

Upon actuating the firing pin to fire, a chambered cartridge, blow-back action is effective to thrust the bolt and the extractor to the left. The extractor claw is in engagement with the rim of the cartridge and the spent cartridge case is blown out of the chamber 22 introducing kinetic energy into the bolt. As the bolt, extractor and the spent case proceed to the left, as viewed in FIG. 1, the inertia ejector remains stationary in the solid line position shown. Ultimately a rim portion 34 of the spent case is brought into contact with'the lip 27 of the inertia rod 26. Upon contact with the rim portion 34, kinetic energy is introduced into the inertia rod; however, the

mass of the rod develops sufiicient resistance to motion so that the cartridge case is abruptly decelerated and caused to pivot about the claw 18. The couple developed, tending to rotate the spent case in a clockwise direction as viewed in FIG. 1, is operative to flip the spent case out of the ejection port 12. Obviously the coil spring 33 offers some resistance; however, it is to be understood that its structure is so light that the'inertia of the member 26 is the predominant force operating to develop the couple.

' Thereafter as the bolt proceeds to the left, a face 36 thereof mates with a corresponding face 37 of the rod operating to drive the member to the left to the dotted line position shown in FIG. 1. When the bolt and ejector are thus disposed the loading port 11 is clear.

Obviously the principles of the ejector device of the present invention may be readily incorporated in a wide variety of firearms. For example, it is not intended that the use thereof be limited to firearms having a blow-back action as shown and described herein.

It is anticipated that a wide variety of adaptations and designs may be devised withoutdeparting from the spirit and scope of the invention.

What is claimed is:

closed position to an open position, an extractor carried 1. In a firearm, a chamber, a bolt movable from a by the bolt, a receiver formed with a loading port and an ejection port, an inertia ejector nested within the bolt and movable from an ejection position wherein said loading port is blocked to a second position wherein the loading port is clear, said bolt and extractor being operable upon firing a cartridge to move relative to said ejector by blow-back action whereby a spent cartridge is free to move into contact with said inertia ejector, said ejector having sufficient mass and being so disposed with respect to said extractor so as to form a couple effective to cast the cartridge out of the ejection port, said bolt being further operable to interlock with said ejector effective to move the ejector to said second position.

2. The device of claim 1 wherein means are provided for positioning the ejector in said ejection position.

3. The device of claim 1 wherein the ejector takes the form of a rod and means are provided for guiding the ejector while moving from the ejection position to said second position.

References Cited in the file of this patent UNITED STATES PATENTS 992,854 Cobb May 23, 1911 1,039,232 Wesson Sept. 24, 1912 1,226,478 Diehm May 15, 1917 1,494J186 Pomeroy May 13, 1924 2,436,937 Rataiczak Mar. 2, 1948 FOREIGN PATENTS 584,039 Great Britain Jan. 6, 1947 746,227 Great Britain Mar. 14, 1956 1,014,464 Germany nu; Aug. 22, 1957 

